The short answer to your question is that the psychological factors (PF) in poker are considerable to a high degree.
It has been said that poker is a mind f*** game played with cards. Online the PF is rather minimized, relative to a live action game. Since a lot of players started online they tend to have a more mathematical dominance in their approach to the game. Even before the poker boom people that were online talking about poker tended to be more technical. The new generation of poker players bought with them to the game an edge that was born of a more mathematical background. As they left their computers and began to play live they have learned the PF side of the game. PF’s are difficult to describe in writing, since PF’s on a high level is more intuitive then technical, so you do not tend to see a lot of questions and answers about it here and at poker forums.
The PF’s in poker to me come across in the context of tells. Tells are what one observes about a player and what one projects to the other players at the game. Everything is a tell about a player. Tells are lies disguised as truth, and truth disguised as lies. The more you understand about a player the more you can clear away the act and get down to the fact. All those things you listed, fear, greed, respect, insecurity etc. are the context of tells. They are generally human emotions, and drivers, they are the reference for the context for tells. Understanding were a player is coming from is important to understanding were they are going and the path they are trying to take. They all add to the accuracy of tells, the more you understand about a player, the more accurate your decisions about the hand can be.
Let me digress, and suggest some reading. The bible of poker books for tells is Mike Caro’s Book of Tells. He writes about player mannerisms and what they mean. Another book I would like to suggest is The Professor, the Banker, and the Suicide King: Inside the Richest Poker Game of All Time. A fun read about a head up 50K/100K limit Texas hold’em game were a syndicate of high limit players went up against a Texas billionaire named Andy Beal. What is interesting in our context is how Beal hid his tells. In essence a baseball cab, sunglasses and a stop watch he used to randomize the time he would take to act on his hand. If you are reading in poker books I would dare say that most have a discussion about the PF’s of poker.
Every player is different. You are I am sure, not me. When it comes to the PF’s of poker I believe that the most important factor is oneself. Everybody needs to approach the game from the point of ones abilities. Some people do well behind the glasses and the hat and the expressionless faces, Chris “Jesus” Ferguson is a player like this. He sits still, says little, the only tell he gives in the game is the time he takes to make a decision on a hand, and it may well be this is not a good indicator of the strength of his hand. Then there is a guy like Mike “The Mouth” Matusow, he really is not capable of closing his mouth. He simply unnerves his opponents and mixes his tells to a rather cryptic level. The important point here is that each of these guys learned to work with the personality they have, and it is what any player who is successful has learned to do.
Most players inherently are able to read other players fairly well. But there are SF’s that keep the majority of players the majority of the time from acting correctly on the information they have. Some are just so much into their own BS that the simply cannot come to the correct decision about what to do at a poker game. They are simply dysfunctional when it comes to understanding what is right under their nose. They might be a beginner who simple does not trust themselves to believe what they see because they have not yet experienced enough context, or they might be an old experienced player who has suffered so many beats, that anything he does see he cannot act correctly on. One of the most common things heard at a poker table is “I Know I am beat but I just have to look you up” and most of the time they are.
Spousal cheating is a great example in the extreme of the psychological phenomenon that keeps people from acting rationally for a while. You have some clue that it is going on, but you simply do not want to believe that it is happening. Because the consequences of it happening means a great loose to you, you want to avoid this loose, you do not want to come to grips of what it means when you lose. Same with poker the inclination is to think in terms of winning, so to think in terms that you might lose is unnatural. When you consider any hand the process is really one of coming to terms with losing the hand, winning the hand is status quote.
Coming back to PF in poker, PF in a live game is one of the most powerful tools you can possess. There is no real argument between what is more important, math or PF, they are both key to a great poker player. Understanding were your player is coming from, not only makes it easier to read them, it also makes it easier for one to take them off their game. All poker players are humans, and as such are not perfect. Even the best players have bad days, and understanding what makes a day bad for them at the table, is just one more way to increase your expectation against them at the table. Having discipline at the table, to do the things in ways that work best for you, is how you defend against the other players. Having an open mind about yourself, your faults, and your strengths is the best way to overcome your weakness and become a strong poker player. All that stuff is in the mind, and all about the psychological factors, and if you cannot overcome them you will not have a shot in the long run of beating the game.